Previously, there is known a fuel supply device that is configured to supply fuel from an inside of a fuel tank of a vehicle to an outside of the fuel tank. The device, which is disclosed in the patent literature 1, includes a sub-tank, a suction filter, a fuel pump, a pressure regulator and a fuel recovery passage portion. The sub-tank stores the fuel. The fuel pump suctions the fuel, which is filtered through the suction filter placed along a bottom portion of the sub-tank. The pressure regulator, which is placed at the outside of the sub-tank, adjusts a pressure of fuel of a pressure-regulation path, which is discharged from the fuel pump and is fed toward the outside of the fuel tank. The fuel recovery passage portion recovers the excess fuel, which becomes excess at the pressure-regulation path, to the sub-tank.
An opening, which is referred to as an excess fuel inflow port, is formed at a peripheral surface of the sub-tank. The fuel recovery passage portion is formed by an excess fuel supply pipe that is in close contact with and is connected to the excess fuel inflow port. The fuel recovery passage portion discharges the excess fuel on the inner side of the opening where the inside of the sub-tank is placed.
In the fuel recovery passage portion of the patent literature 1, since the excess fuel supply pipe is in close contact with and is connected to the excess fuel inflow port, once vapor contained in the excess fuel enters the inside of the sub-tank, the vapor is less likely outputted to the outside of the sub-tank. When this vapor is suctioned into the fuel pump through the suction filter once again, the fuel supply stability is deteriorated.